Alert archive / Texas / Red Flag Warnings in 2018

Red Flag Warning 7, NWS Austin/San Antonio, TX

December 20, 201819 counties in Texas

NWS Austin/San Antonio, TX issued this red flag warning at Dec 20, 2018, 3:15 PM CST for 19 counties in Texas. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 20, 2018, 3:15 PM CST (21:15 UTC)
Expired
Dec 20, 2018, 6:00 PM CST
In force
3 hr
Issued by
NWS Austin/San Antonio, TX

Counties Atascosa County, TX, Bandera County, TX, Bexar County, TX, Comal County, TX, Dimmit County, TX, Edwards County, TX, Frio County, TX, Guadalupe County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, Maverick County, TX, Medina County, TX, Real County, TX, Uvalde County, TX, Val Verde County, TX, Wilson County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 99 km from the middle of the area, began a volume at 21:14 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Del Rio, TX (KDLF), launched 12:00Z, 9.3 hours before the alert went out and 153 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Del Rio, TX at 12:00Z on 2018-12-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 12:00Z on 2018-12-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -129 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1702 m above ground
0-6 km bulk shear
82 kt
0-1 km storm-relative helicity
-129 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

136 
WWUS84 KEWX 202115
RFWEWX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Austin/San Antonio TX
315 PM CST Thu Dec 20 2018

TXZ183>187-189-202>207-217>222-228-210000-
/O.NEW.KEWX.FW.W.0007.181220T2115Z-181221T0000Z/
Val Verde-Edwards-Real-Kerr-Bandera-Kendall-Kinney-Uvalde-Medina-
Bexar-Comal-Guadalupe-Maverick-Zavala-Frio-Atascosa-Wilson-Karnes-
Dimmit-
315 PM CST Thu Dec 20 2018

...RED FLAG WARNING IN EFFECT UNTIL 6 PM CST THIS EVENING FOR
WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS OF THE HILL COUNTRY...
RIO GRANDE...WINTER GARDEN...BRUSH COUNTRY...AND I-35 CORRIDOR...

The National Weather Service in Austin/San Antonio has issued a
Red Flag Warning for wind and low relative humidity, which is in
effect until 6 PM CST this evening.

* WINDS...Northwest 15 to 25 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...15 TO 25 percent.

* IMPACTS...Any fires that develop will likely spread rapidly. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now....or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$
1 follow-up statement
019 
WWUS84 KEWX 202358
RFWEWX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Austin/San Antonio TX
558 PM CST Thu Dec 20 2018

TXZ183>187-189-202>207-217>222-228-210100-
/O.EXP.KEWX.FW.W.0007.000000T0000Z-181221T0000Z/
Val Verde-Edwards-Real-Kerr-Bandera-Kendall-Kinney-Uvalde-Medina-
Bexar-Comal-Guadalupe-Maverick-Zavala-Frio-Atascosa-Wilson-Karnes-
Dimmit-
558 PM CST Thu Dec 20 2018

...RED FLAG WARNING WILL EXPIRE AT 6 PM CST THIS EVENING FOR  
PORTIONS OF THE HILL COUNTRY...RIO GRANDE...WINTER GARDEN...BRUSH 
COUNTRY...AND I-35 CORRIDOR...

Wind speeds and gusts will continue to diminish through the 
evening hours to less than 15 mph and less than 10 mph overnight. 
Relative humidity values will recover to around 65 to 75 percent 
overnight.

$$

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 20, 3:38 AM CSTWind AdvisoryEWXAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 19 more14 hr

Nearby

Red Flag Warnings in Texas, 2018Every red flag warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.